A mobile phone (for example, a fixed mobile convergence (FMC) terminal, and a dual terminal) having a public network having a wide area (for example, freedom of mobile multimedia access (FOMA)), and a wireless communication network having a small area such as wireless local area network (WLAN) has been known. Such a mobile phone makes a call by data communication and voice over internet protocol (VoIP) in a communication area of WLAN-Access Point (AP), and performs operation of receiving Beacon in the absence of a call by the data communication and the VoIP. In the area outside WLAN-AP, the operation of receiving Beacon is stopped, and operation of scanning outside the WLAN area is performed regularly (see FIG. 19). A scan interval of the scan operation is set shorter so that connection can be established soon after entering the WLAN-AP.
When a mobile terminal is out of the WLAN-AP, a power source for WLAN can be turned off manually, but if a user forgets to turn off the power source, the scan operation is performed, and unnecessary electricity is consumed (see FIG. 20). For example, the user goes to a business trip without turning off the power source for WLAN, electricity is consumed by unintended scan operation, and the mobile terminal cannot be used as a telephone.
Technologies for solving unnecessary scan operation include a method disclosed in Japanese Laid-open Patent Publication No. 2007-116294 in which a contactless integrated circuit (IC) card is attached to a terminal, an entrance/exit managing apparatus (card reader) is prepared, IC card information is rewritten at the time of exit, and thereby a power source for WLAN is turned off. Moreover, Japanese Laid-open Patent Publication No. 2006-295643 discloses a method of turning on/off the power source for WLAN by a mobile phone base station notifying the terminal of a wireless LAN base station information in the base station.
As a technology for solving unnecessary scan operation, Japanese Laid-open Patent Publication No. 2006-13594 discloses a method of increasing the scan interval gradually, reducing the number of times of the scan operation, and suppressing consumed electricity. Japanese Laid-open Patent Publication No. 2005-229399 discloses a method of turning on/off the power source for WLAN by acquiring position information using global positioning system (GPS), and specifying WLAN areas.
With the technology disclosed in Japanese Laid-open Patent Publication No. 2007-116294, many additional facilities are required and the cost increases because an entrance/exit managing apparatus needs to be provided. Besides, with the technology disclosed in Japanese Laid-open Patent Publication No. 2006-295643, it is not suited for the access point for use by a corporation (company) and an individual and a complicate system architecture including a carrier is necessary because a mobile phone base station notifies a terminal of wireless LAN base station information in the base station.
With the technology disclosed in Japanese Laid-open Patent Publication No. 2006-13594, response at the time of restoration deteriorates because a scan interval is increased gradually. With the technology disclosed in Japanese Laid-open Patent Publication No. 2005-229399, electricity is consumed for position detection by GPS because position information is acquired by using GPS.